Absorbable multifilament sutures are known in the art. Such sutures include DEXON® sutures (made from a glycolide homopolymer and commercially available from Davis & Geck, Danbury, Conn.), VICRYL® sutures (made from a copolymer of glycolide and lactide and commercially available from Ethicon, Inc., Sommerville, N.J.), and POLYSORB® sutures (also made from a copolymer of glycolide and lactide and commercially available from United States Surgical Corporation, Norwalk, Conn.). These sutures are sometimes referred to as short term absorbable sutures, i.e., sutures which retain at least about 20 percent of their original strength at three weeks after implantation, with the suture mass being essentially absorbed in the body within about 60 to about 90 days post implantation.
Suture coatings for synthetic absorbable multifilament sutures are also known and are frequently utilized to improve physical characteristics of the sutures, including their knot tie-down properties. Known coatings include copolymers and homopolymers of glycolide, lactide, caprolactone, trimethylene carbonate, and dioxanone, as well as mixtures and blends thereof. For example, U.S. Pat. No. 5,123,912, the entire disclosure of which is incorporated by reference herein, discloses a bioabsorbable coating composition for surgical sutures which can be either a copolymer of a low molecular weight polyalkylene glycol, a glycolide monomer and a lactide monomer, or a copolymer of a low molecular weight polyalkylene glycol and a preformed copolymer of lactide and glycolide.
One problem with any surgical device, including sutures, is the potential for bacteria to adhere to the device and utilize the device as a means to enter the surrounding tissue in a patient. Known synthetic absorbable multifilament sutures do not yet provide effective levels of antimicrobial activity for the period of time the suture is in place. Therefore, contamination and infection can occur at the wound site prior to the complete healing of the wound closure.
Accordingly, there is a need for synthetic absorbable multifilament sutures that can remain in vivo for extended periods of time with enhanced antimicrobial efficacy. There is also a need for an easy and inexpensive method of applying an antimicrobial agent to a suture that provides protection against microorganisms for extended periods of time.